Abstract

                                The efficiency of three herbicides viz., fluchloralin (0.90 kg ha''), thiobencarb (1.25 kg ha) and metolachlor (1.00 kg ha¹) on weed characteristics such as weed flora, relative density and relative dry weight of weeds, weed control efficiency, weed index and gran yield of three green gram cultivars viz., Co 4. NARP I and Co GG 89047 were evaluated in the field conditions. Among them, metolachlor followed by fluchloralin and thiobencarb reduced the relative density and relative dry weight of weeds over unweeded control. The sedge (Cyperus rotundus) was dominant followed by broad leaved weeds viz. Tranthenia portulacastrum and Amaranthus viridis). The broad leaved weeds contributed more dry weight because of their expanded leaf area and faster growth rate. The pre-emergence application of metolachlor followed by pre-sowing incorporation recorded maximum weed control efficiency and was on par with hand weeding. Higher weed index was observed in unweeded control irrespective of cultivars and the least was in metolachlor and this lead to higher grain yield in metolachlor treatment. Among the cultivars used, Co GG 89047 was found to be best and recorded higher grain yield.

Key words : Herbicides, impact, weeds, green gram, yield